U-bolt clamp assembly

ABSTRACT

A saddle for a U-bolt clamp is formed from a sheet metal blank rolled at its ends in opposite directions to provide tubular portions which receive the bolt legs in axially slidable relation. Under the clockwise torque transmitted to the ends of the tubular portions as the securing nuts are drawn up on the bolt legs against the saddle, the force exerted on both legencompassing tubular portions of the saddle will act to wind or constrict both tighter on the bolt legs or at least will prevent them from twisting loose on the legs. The web of the saddle is reinforced by an integral portion extending between the bolt legs.

United States Patent Dowling et al. Nov. 2%, 1973 U-BOLT CLAMP ASSEMBLY3,605,214 9/1971 Spotts et al. 24/277 Inventors: William E. g; WilliamR. 3,604,676 9/1971 Weber 248/72 X Heckethom, both of Dyersburg, TenthPrzmary Exammer-Donald A. Gnffin Attorney-Robert I. Dennison et a1. [73]Assignee: Heckethorn Manufacturing Co.,

Dyersburg, Tenn. ABSTRACT 22 F1 d: A 31 1972 I 1 16 A saddle for aU-bolt clamp is formed from a sheet [21] Appl. No.: 285,223 metal blankrolled at its ends in opposite directions to provide tubular poitionswhich receive the bolt legs in axially slidable relation. Under theclockwise torque (gill. transmitted to the ends of the tubular portionsas the [58] i 285/199 securing nuts are drawn up on the bolt legsagainst the 248/72 saddle, the force exerted on both leg-encompassingtubular portions of the saddle will act to wind or constrict bothtighter 0n the bolt legs or at least will pre- [56] References cued ventthem from twisting loose on the legs. The web of UNITED STATES PATENTSthe saddle is reinforced by an integral portion extend- 2,693,97511/1954 Smith 285/199 X i b t th b lt l 3,137,053 6/1964 Osborn et a1.3,284,866 11/1966 Zimmerman 24 277 6 Claims, 6 Drawing Figures U-BOLTCLAMP ASSEMBLY BACKGROUND The field of the present invention is the artof clamps for holding sections of tubing in telescoped connection,generally referred to as U-bolt clamps, or saddle clamps. Such devicesare commonly employed in exhaust systems of vehicles.

The prior art directly concerned with such clamps is for the .mostpartderivedrfrom a basic assembly comprising a saddle .member formed ofsheet metal with spaced tubular portions connected in parallel relationby a web integral'therewith and having a semicircular edge curved on theradius of the bight of a U-bolt with parallel legs axially slidable inthe tubular portions. The free ends of the legs are threadedforreception of nuts that are tightened up against the tubular portionsof the saddle member through lock washers to clamp together a couplingof telescoped tubes, such as exhaust pipes, disposed between the bightof the bolt and the curved edge-ofthe saddle member. In known clamps ofthis type which most closely approach'the present invention, the saddleweb and tubular portions are formed from a flat blank of thin sheetsteel stamped or cut substantially as illustrated in U.S. Pat. No.3,137,053. The tubular portions of the saddle web which receive the legsof the U-bolt are rolled so that their axial terminal edges are bothclosely adjacent the same side face of the web. When the securing nutsare drawn up to clamp the telescoped tubular members between the bightof the U-bolt and the curved edge of the saddle member, the incidenttorque imposed on both tubular portions will be clockwise, in the samedirection. Accordingly, one tubular portion will tend to wind tighter onits supporting bolt leg while the other tubular portion will tend tounwind and become loosened on its leg; the distribution and intensity ofthe forces acting on the thin saddle web as the nuts are progressivelydrawn tighter then differ substantially in the vicinity of theirrespective tubular portions, so much so that buckling or otherdistortion of the saddle web has been known to occur during tighteningof the nuts and is likely to occur as a consequence ofsthe inevitableresolution of forces that follows forcible adjustments in assemblies ofmetal elements. Furthermore, any unwinding of one of the tubu-- larportions impairs the efficiency of the telescoped tube seal that iseffected by the compressive force applied by the upper ends of thetubular portions when the securing nuts are fully drawn up, which mannerof sealing is characteristic in clamps of the aforesaid prior art type.

SUMMARY OF THE INVENTION The U-bolt clamp of the present invention isgenerally similar to the aforesaid prior art clamp in appearance,function, structure and operation, but differs markedly therefrom inthat it has none of its apparent or potential disadvantages. The presentclamp as herein disclosed is constructed and arranged so that neithertubular portion of the saddle web can be subjected to unwinding stressesduring tightening of the securing nuts, and also in that the saddle webis reinforced against possibility of buckling or other distortion by thehigh torque forces applied in tightening the nuts.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a preferredembodiment of the present invention.

FIG. 2 is a side elevation thereof.

FIG. 3 is a sectional view on line 3-3 of FIG. 2.

FIG. 4 is a sectional view on line 4-4 of FIG. 2.

FIG. 5 is a side elevation of a variant of the clamp.

FIG. 6 is a sectional view on line 66 of FIG. 5.

DETAILED DESCRIPTION The invention herein disclosed is an assembly ofsix separate parts: a U-bolt 10, a saddle 11, two securing nuts 12, andtwo lock washers 23. The nuts are threaded on the free ends of the legs13 which extend in parallel relation from the semicircular bight 14 ofthe bolt. The saddle is slidable axially on the legs between thesecuring nuts and lockwashers and the bight of the bolt. In operation, acoupling of telescoped tubular members is compressed between the saddleand the bight when the saddle is moved toward the bight under thepropulsion force of the nuts as they are drawn up on the legs.

A salient feature of the present invention is the construction of thesaddle 11. This is formed from an initially planar, oblong, sheet steelblank that is rolled at each end to form an integral, full circle loopthat is bisected by the plane of the blank. These loops constitutetubular portions 15 and 16 which receive the bolt legs 13 in axiallyslidable relation when the saddle is mounted on the bolt. As hereinshown, the ends of the tubular portions which extend along the bolt legsin the direction of its bight, herein called upper ends, are constitutedin a known manner to effect a compression seal on a telescoped tubecoupling to which the clamp may be applied. The opposite, lower ends, ofthe tubular portions are flush in a plane that is normal to the axis ofeach bolt leg when the saddle is mounted on the bolt.

It will be seen that the end extremity of the blank at each of thetubular portions 15 and 16 provides an axially extending terminal edge17 that is directed against the proximate side face of the blank butwhich is not attached thereto. The planar body of the blank between theterminal portions 15 and 16 constitutes a web 18 having a semicirculartop edge 19 curved on the radius of the bight 14 and complementalthereto, so that together the bight and the saddle edge 19 deliniate thecircumference of a circle equal in diameter to the external diameter ofthe outer tube of a telescoped tube joint (not shown) clamped betweenthe bolt and saddle.

In the form of the invention illustrated in FIGS. 1-4, the saddle web isdoubled upwardly upon itself for a portion of its length to providelongitudinal reinforcement means 20 in the form of a flat strip having astraight upper edge 21 that lies in a plane normal to the axis of eachof the tubular portions 15 and 16, and spaced a short distance below thebottom of the semicircular edge 19, preferably about 1/32 of an inch.

In the variant of the invention shown in FIGS. 5 and 6, the onlydifference from the previous form is in the means for reinforcing thesaddle web 18. In this variant, the bottom of the web is extendeddownwardly in the plane of the web to provide a reinforcing enlargement22 extending below the plane of the bottom ends of the tubular portions15 and 16.

Whatever form the saddle 11 may take in possible different embodimentsof the invention, the tubular portions 15 and 16 must be so rolled orwound that the clockwise torque transmitted to their flush bottom endsby the securing nuts 12 and lockwashers 23 when they are drawn upagainst the saddle must always be exerted in such direction that bothtubular portions will tend to wind or constrict clockwise on theirrespective bolt legs, as viewed from the nut end. In order to achievethis, not only must the axial terminal edges 17 of the tubular portions15 and 16 be at opposite sides of the saddle web 18, but the initialdirections in which they are curved must be relatively reversed withrespect to a predetermined point of reference. In the present invention,this point of reference is the line of perpendicular intersectionbetween the plane of the web 18 and the plane common to the bottom endsof the tubular portions 15 and 16. From this point of reference theloops constituting both of the tubular portions are trained clockwise,so that the terminal edges 17 of the tubular portions will be atoppositesides of the web. We have discovered that the precise arrangement justdescribed is the only arrangement by which torque exerted on the bottomends of the bolt leg encasing tubular portions of saddles as thesecuring bolts are drawn up can be made effective to prevent bothtubular portions from tending to loosen on their respective U-bolt legs.

We claim:

1. In a U-bolt clamp assembly having a U-bolt, said U-bolt comprising abight portion and a pair of legs, a pair of tubular portions axiallyslidable on said legs, a saddle web integral with and spanning the spacebetween said tubular portions, and securing nuts threaded on the freeends of the bolt legs for drawing up against the adjacent ends of thetubular portions; the tubular portions in cross section being unclosedloops trained clockwise in opposite directions from the saddle web.

2. In the clamp assembly of claim 1, said saddle web being planar, theends of the tubular portions proximate the securing nuts being in aplane common thereto and which is perpendicular to the plane of the web,each tubular portion being in cross section a circular loop bisected bythe plane of the web, one loop being trained initially clockwise fromone side of the web, and the other loop being trained initiallyclockwise from the opposite side of the web.

3. A U -bolt clamp saddle comprising a planar sheet metal blank, a pairof tubular portions thereon in parallel spaced relation thereon andintegral therewith, one tubular portion being in cross section aclockwise trained loop open at one side of the blank, and the othertubular portion being a clockwise trained loop in cross section and openat the other side of the blank.

4. A U-bolt clamp saddle comprising a planar, oblong sheet metal member,said member having a relatively thin web portion of uniform thicknessforming a work engaging edge portion, and a tubular portion at each endof said member, said tubular portions each adapted to receive a legportion of a U-shaped bolt to form an opening to receive the work, andreinforcement means formed integral with said oblong member for anappreciable extent at the lower portion thereof and closely adjacent thelower end of said tubular portions receiving the leg portions of theU-shaped bolt, said reinforcing means being distally spaced below thework engaging edge portion, said reinforcement means being an edgeportion of the blank doubled back upon itself.

5. In the clamp saddle of claim 4, the blank having a work indentingedge portion spaced above the edge of said doubled back portion, theindenting edge being curved and the doubled back edge being straight.

6. A U-bolt clamp saddle comprising a planar, oblong sheet metal member,said member having a relatively thin web portion of uniform thicknessforming a work engaging edge portion, and a tubular portion at each endof said member, said tubular portions each adapted to receive a legportion of a U-shaped bolt to form an opening to receive the work, andreinforcement means formed integral with said oblong member for anappreciable extent at the lower portion thereby and closely adjacent thelower end of said tubular portions receiving the leg portions of theU-shaped bolt, said reinforcing means being distally spaced below thework engaging edge portion, said reinforcement means being a downwardlyextending enlargement of the blank in the plane thereof.

1. In a U-bolt clamp assembly having a U-bolt, said U-bolt comprising abight portion and a pair of legs, a pair of tubular portions axiallyslidable on said legs, a saddle web integral with and spanning the spacebetween said tubular portions, and securing nuts threaded on the freeends of the bolt legs for drawing up against the adjacent ends of thetubular portions; the tubular portions in cross section being unclosedloops trained clockwise in opposite directions from the saddle web. 2.In the clamp assembly of claim 1, said saddle web being planar, the endsof the tubular portions proximate the securing nuts being in a planecommon thereto and which is perpendicular to the plane of the web, eachtubular portion being in cross section a circular loop bisected by theplane of the web, one loop being trained initially clockwise from oneside of the web, and the other loop being trained initially clockwisefrom the opposite side of the web.
 3. A U-bolt clamp saddle comprising aplanar sheet metal blank, a pair of tubular portions thereon in parallelspaced relation thereon and integral therewith, one tubular portionbeing in cross section a clockwise trained loop open at one side of theblank, and the other tubular portion being a clockwise trained loop incross section and open at the other side of the blank.
 4. A U-bolt clampsaddle comprising a planar, oblong sheet metal member, said memberhaving a relatively thin web portion of uniform thickness forming a workengaging edge portion, and a tubular portion at each end of said member,said tubular portions each adapted to receive a leg portion of aU-shaped bolt to form an opening to receive the work, and reinforcementmeans formed integral with said oblong member for an appreciable extentat the lower portion thereof and closely adjacent the lower end of saidtubular portions receiving the leg portions of the U-shaped bolt, saidreinforcing means being distally spaced below the work engaging edgeportion, said reinforcement means being an edge portion of the blankdoubled back upon itself.
 5. In the clamp saddle of claim 4, the blankhaving a work indenting edge portion spaced above the edge of saiddoubled back portion, the indenting edge being curved and the doubledback edge being straight.
 6. A U-bolt clamp saddle comprising a planar,oblong sheet metal member, said member having a relatively thin webportion of uniform thickness forming a work engaging edge portion, and atubular portion at each end of said member, said tubular portions eachadapted to receive a leg portion of a U-shaped bolt to form an openingto receive the work, and reinforcement means formed integral with saidoblong member for an appreciable extent at the lower portion thereby andclosely adjacent the lower end of said tubular Portions receiving theleg portions of the U-shaped bolt, said reinforcing means being distallyspaced below the work engaging edge portion, said reinforcement meansbeing a downwardly extending enlargement of the blank in the planethereof.